Fillercap mechanism



Dec. 12,

1950 M. M. CULVER ETAL FILLER CAP MECHANISM Filed Dec. 50, 1944 L I jg)"mu-q Patented Dec. 12, 1950 UNITED STATES FILLER-CAP MECHANISM MerlynM. Culver and Lyle L. Duncan, Dayton, Ohio 3 Claims. 1

This invention relates to a readily removable covering or closure devicesuch as the filler cap for use with liquid cooling systems for internalcombustion engines, such as liquid cooled airplane engines, and moreparticularly for such cooling systems which are of the closed type inwhich substantial pressure is normally present in the cooling systemduring operation.

One of the principal objects of the invention is to provide a closuremechanism constructed for use with the cooling liquid supply inlet ofsuch a system, which will seal the system effectively over the range ofpressures existing during periods of operation as well as during standbyor non-operating periods but which may be readily and easily actuated topermit access to the cooling system when desired.

Another object of the invention is to provide a filler cap or covermember construction which will automatically seal adequately at very lowpressures, even negative pressures, and in which the efiectiveness ofsealing will vary or increase with variations or increases in pressurein the cooling system, so that operatively tight sealing may be readilyeifected throughout a wide operating range in a given engine and coolingsystem, or different ranges in differing cooling systems and differentdevices with which such systems are used.

Another object of the invention is to provide the filling opening ofsuch a system with an inner closure member which is urged toward sealingposition by spring pressure means adequate to effect sealing undernon-operative pressures and which is also additionally urged towardsealing position by any pressure in the system resulting from thecooling medium so that the sealing elfect increases as the systempressure increases, and also to provide a readily removable outer membercovering over the inlet opening to the cooling system and havingdetachable connection with the first said member and in which the secondmember is not subject to such pressures as may be exerted against thefirst member and which may thus be readily removed.

Other objects and advantages will be apparent from the followingdescription and claims and the drawing.

In the drawing, which illustrates a preferred embodiment of theinvention, and in which like characters of reference designate likeparts throughout the several views thereof- Fig. 1 is a verticalsectional view, along the line l-I of Fig. 3, through the inlet intosuch a pressure cooling system for an engine showing the closuremechanism in place and in closed position;

Fig. 2 is a vertical sectional view at right angles to the plane of Fig.1, along the line 2-2 of Fig. 1;

Fig. 3 is an inverted plan view of the closure mechanism;

Fig. 4 is a top plan view partly broken away of the closure mechanism;

Fig. 5 is an inverted section of the closure mechanism taken on the line5--5 of Fig. 1 looking in the direction of the arrows but omitting thefilling inlet or threaded neck; and

Fig. 6 is an enlarged fragmentary section showing certain details ofconstruction.

The modern liquid cooled airplane engines, and some automobile engines,use closed cooling systems which are provided with a cover or closuremember, ordinarily referred to as a filler cap, for the inlet throughwhich the cooling medium is introduced. In modern high-powered liquidcooled airplane engines, which operate under extraordinary conditions ofheavy load, quite substantial pressures will be built up duringoperation, at times as high as 50 pounds per square inch against thefiller cap. In usual practice the filler cap in such engines has been aform of threaded closure plug, adapted to be screwed into threadedengagement with either internal or external threads on a flange or pipesurrounding the filling opening to be sealed tightly against such hi hpressures by means of a gasket or machined fit metal surfaces broughtinto sealing contact by screwing the closure plug or cap sufficientlytight down against the filler flange or pipe of the system. In someinstances where small pressures are encountered the filler cap has beenheld in position by means of a bayonet slot connection; but where highpressures and the necessity for absolute certainty in sealing the liquidcooling system exists, as in liquid cooled airplane engines, it has beenthe universal practice to have filling plugs which could be screwed downtightly enough to make an effective seal against leakage even at thehigh pressures referred to. Such filler caps for high pressure coolingsystems have had as very serious ebjections, first that to secure thepressures necessary for effecting the tight seal requires the use ofwrenches or special tools, and when the caps are to be removed not onlysimilar wrenches or special tools must be used but the frictionalresistance or binding may be so great, especially in liquid cooledairplane engines, that hammers or other tools may be required to removethem,

and as a result they are frequently ruined or so damaged that they havea very short life and require constant replacement. In engines forfighter airplanes and the like it is well known that during the courseof combat they may have to return to base for refueling and recheckingand to pick up additional ammunition and that the time element isextremely important. Under such circumstances the pressure in thecooling system is apt to be quite high and the time element does notpermit of the plane remaining on the ground long enough to allow it tocool off. And with the parts expanded due to heat there is sometimes atendency to distortion and binding so that the large frictional forcesnecessary for adequate sealin with the usual type of filler cap are attimes greatly increased; When the time element is especially importantthis brings about the use of hammers or other tools referred to andfrequently leads to such destruction of the filler cap that in a shorttime it becomes no longer sufliciently effective for sealing or is sobattered up that it cannot be properly sealed or removed. Conditions.such as that would be especially true in very hot climates, in desertwarfare, and in places like the South Pacific where planes may have toland and take 01? with great rapidity without the necessary tools andequipment being present. And even where the tools are available,frequently they may not be readily at hand and the same results mayensue. And, of course, the necessity for having special tools or ofhaving the formerly usedcaps badly battered up is very objectionablebecause of the necessity for transporting replacement parts all over theworld and having them available at all times. Secondly, as is well knownthe cooling fluid even at low pressures can develop vapors or steam ofvery high temperature, and when the cap is removed there is greatlikelihood of the operator or mechanic being severely injured or burned.With high pressure fluid systems there is still the third danger thateven if the temperature is not high enough to cause burns the pressuremay be so great that as the cap is released from the threads it may beblown away with great force, lacerating or breaking the mechanic hands,or causing severe injury to the mechanic or someone standing nearby. V

The present invention provides a closure construction which iscompletely adequate for effective sealing of these pressure coolingsystems, under any pressures of use, which utilizes the internalpressure to supplement the sealing effected by the structure itself, andwhich is so constructed that opening and closing of the filling openingmay be effected without the necessity of unscrewing parts tightly heldtogether, as described above, thus leaving all of the necessary parts sothat they may be readily placed in position or removed by mere handmanipulation and without the difiiculties and dangers above referred to.

The drawing illustrates a preferred embodiment of the invention whichhas been found very satisfactory for use with liquid cooled airplaneengines such as those which power the so-called P38, P40 and P- 5lpursuit planes, which will withstand the highest pressures encounteredin the cooling systems of suchv engines, and which nevertheless is verysimple and readily operated and is entirely free from the objectionsreferred to above.

4 ,y In the drawing a small portion of the cooling system of such anengine is shown and designated by the numeral It, the filling pipe orflange which surrounds the inlet opening being designated by the numeralII. The entire engine and liquid cooling system and other parts thereofare thought unnecessary to illustrate. As illustrated the part I I isinteriorly screw threaded as shown at 2, to receive a closure member,the main body of 'WhiCh'ls designated generally by the numeral 26 andhas an externally screw threaded annulus 26 which is mounted in thescrew threads I2 of the filling pipe. This closure member is providedwith a hexagonal rim 22 whose outer faces serve as seats for a wrench.An annular gasket723 is mounted about the annulus 2i and against theunder face of the hexagonal rim 22 so that when the closure member '20is screwed down tightly against the gasket, a tight seal is providedwhich prevents the escape of any vapors or steam through this threadedjoint. Immediately adjacent the lower face 24, a groove is formed, as bymachining, to provide a seat to hold the gasket '23 in place above thethreads, and'so that it will not be dislodged or lost from the closuremember during transportation or when being inserted into the inletopening in'place 0f the regularly used filler cap, or removed for anypurpose. The closure is provided with an opening 25 through which theradiator may be filled. Close to the edge of this opening there is cut agroove 27 (Fig. 6) which is undercut on the side away from the openingas shown at 28. Into this groove is placed an annular gasket 29 andthelower edge '30 of the filling opening is peened upon and holds thegasket firmly in place.

In order to form a positive and effective sealing mechanism for thisopening, and one in which the sealing effectiveness increasesproportionately with any increases in pressure in the operating rangeofthe engine coolingsystem and which is so constructed that ready accessmay be had to the cooling systeminlet without the use of special toolsor damage to the sealing mechanism, the cooling mechanism comprises amovable sealing member, shown as a flap valve 3! which is providedwith astrengthening rib 32 and is pivotally mounted by arms 33, ion the pintle-35, which latter in turn is mounted in the body of the closuremechanism through holes 35 provided in the annulus for that purpose. Thetop surface of the flap 3| makes contact with the gasket 29, around the-opening 25, -under the thrust of springs '49 which are coiled about thepintle 3.5,are braced at one end against the bottom face of the flap 3!and at the other end against the annulus Z-lof the closure, theconstruction being such, that the springs are under tension and thusurge the flap 31 into sealing contact against the gasket 29. Thesesprings may satisfactorilybe so constructed as to apply about threepounds per square inch pressure against the gasket29, a pressure whichof itself has been found in practical useand under test adequate toinsure sealing of-the systems ofsuch airplane engines at ordinarystandby pressures, or even vatsomewhat reduced pressures, effective inthe cooling system against the sealing mechanism. When pressures againstthe sealing mechanism increase they bear against :the fiap 3i and thusprogressively increase the effectiveness .of the seal. As the pressuresincrease the summation of the springpressure plus that made effective bythe cooling fluid maintain sealing effectiveness which varies orincreases in step with variations or increases in the pressures tendingto escape.

Mounted on the top of member 3| are oppositely extending flat arms, ordetent lugs, formed integral with the upstanding portion 43 which inturn is integral with the main portion of the member 3|. These lugs orextensions Al, 42 are spaced from the top of the main body of member 3|and thus serve to receive beneath them portions of the outer cover 55whereby the cover is impositively locked in place and the urge of thesprings it! is supplemented.

The outer cover need not be as strongly constructed or of assatisfactory material as the sealing flap valve 3| and the adapter orclosure member to which it is pivoted because the forces and pressuresto which it is subjected are comparatively light. As will be seen solong as the member 3| seals tightly against the gasket 29, none of thepressure inside the cooling system is exerted against this cover member56. This cover member is shown as made of a metal stamping which isprovided with an annular step or shoulder portion 52 and with anexterior flange 53 which is held within the beaded-over edge 56 of thetop piece 55. This cover is attached to the closure member by a chain52, so that it will not become lost in ordinary operations. In Fig. ithe top member 55 is broken away to disclose the inside of the member 5|and its relation with respect to the lugs or arms 4 i 42.

As shown in Fig. 4 the metal stamping 5| has an annular, extendedportion 56 of dimensions such as to extend down into the opening 25 andwhich has an end closure having an elongated opening 55' which can bealigned with and is of such dimensions that it can be passed down overthe cross arms or lugs 4|, 42. By positioning the coverso that theelongated opening 55 will pass down and receive the arms 4|, 42 thecover may then be given an angular turn of approximately 90 which willplace the opening 55 crosswise of the lugs M, 52 as shown in thefigures, the surrounding portion of the end closure thus moving betweenthe arms ll, 42 and top of the main portion of the member 3|. The metalat the diagonal corners 5T, 59 of the elongated opening 55' is depressedto form two cam-like engaging faces for the adjacent bottom faces of thecorresponding ends of the arms or lugs 4|, 52 so that as the outermember 55 is turned the lugs will ride up smoothly onto and into correctposition on the end closure of member 5|.

By proper proportioning of the member 5|, the part 52 may rest againstthe top of the member and the spring of the end extension of member 5!may cause sufficient frictional resistance, as between the severalcontacting surfaces, to hold the outer cover against accidentaldisplacement and also to give an upward lift to 3| to supplement theurge of the springs 40.

Preferably, however, the alternative and additional means shown may beprovided. In this construction passages 5| are drilled or otherwiseformed in the closure which house spring pressed balls 53, 64,respectively. Cooperating dents 65, 55 are made in the step part 52 ofthe closure member 55. This construction serves not only as animpositive lock to hold the outer member in position against accidentalturning, but also serves to inform the mechanic who replaces the member55 when the locking pieces are in correct relationship. The pressure ofthe springs 6 can be changed to apply greater Or less supplementalpressure to the member 50, to supplement the pressure of the springs 40.

The closure may be installed as a part of the original equipment of thecooling system or as a replacement. When it is desired to fill thecooling system the top cover 50 can be removed by hand without the useof a wrench, since it is subjected to substantially no pressure otherthan the frictional resistance referred to, and is free from thepressure in the cooling system because of the sealing action of themember 3|. When this is done the flap closure 3| will remain closed andsealed without danger of burning or injuring the mechanic. If thecooling fluid is cool the mechanic thrusts the spout of the filling hoseagainst the top of the cross arms of closure means 3|, which opens withcomparative ease, to permit adding cooling liquid to the system. Thesearms 4|, 42 are so extended that the filling spout will not strikeagainst or damage the top surface of 3| which seats against the gasket29, and thus effective sealing is insured. If the cooling fluid is hotand the pressures within the system are great, the mechanic can stand ata distance and depress the member 3| by means of a tool, until excessivepressures have been relieved and without any danger of injury. Generallysuch airplane engines are not supposed to be opened when hot; butsometimes, as in the emergency of combat conditions sufficient time isnot available to permit cooling. For such emergency conditions thecooling system may be provided with a safety or pressure release valve10 shown diagrammatically, which may be operated by the mechanic toreduce the pressures therein before operating of the closure isattempted. And also even with very high pressures extra tools orequipment is not necessary to open the closure member 3|, as the spoutof the hose or container for the cooling liquid will ordinarily exertadequate pressure to effect opening, without any danger or injury to theoperator.

The present invention provides also that dirt, sand which is everpresent in desert warfare, and other extraneous materials are excluded,so that the closure would not be gummed or clogged up and will be readyfor satisfactory and easy use under adverse conditions of weather, etc.,and under the most rigorous conditions of service. The outer cover isheld against being dislodged accidentally or by carelessness on the partof the workmen, by means of the spring pressed detent balls or byfrictional resistance and yet may be readily opened for refillingwithout any special tools, and long life and certainty of operation aresecured. It should be noted that the action of the detent balls tends toswing the closure member 3| about its pivot 35 due to the resilientfrictional portions of the end of the extension 56; but internalpressure upon the closure member 3| as it increases tends to swing thatmember upwardly slightly as the sealing gasket 29 is compressed, andthus tight sealing closure is secured without any undue frictionalresistance being placed upon turning movement of the outer cover 50. Thefrictional resistance, or spring detent balls, hold the outer coveragainst being dislodged accidentally or by carelessness on the part ofthe workmen.

The spring detent balls act as an impositive stop to indicate theposition to which the outer cover should be turned. If for any reason,however, the mechanic turns the Outer cover to overrun the detent balls,the upwardly extending members 586il serve as stops against which theextensions 41-42 will strike so that there is a definite and positivelimit to the turning member, so located that the outer cover will beheld tightly in place, and if it tends accidentally to turn in theopposite direction such turning movement Will be automatically stoppedwhen it reaches the spring pressed detent balls. The construction thusis essentially'simple and yet quite effective over a wide range ofpressures in the cooling system, and does not require close machining orcomplex replacement parts. Also the closure will remain effective eventhough the outer cover is lost or destroyed and the closure willmaintain its seal even at low pressures.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise formof apparatus, and that changes may bemade therein without departing from the scope of the invention which isdefined in the appended claims.

What is claimed is:

1. A closure for cooling systems for engines in which a liquid coolingsystem is operable at considerable internal pressure, and having aninlet opening into such system, comprising a closure mechanism thereforhaving an opening, means to mount a gasket about said closure opening,means to close one side of the closure opening comprising a pivotallymounted spring pressed member, oppositely extending arms carried by saidspring pressed member extending into said opening, said spring pressedmember having a sealing face for cooperation withthe gasket, means toclose the other side of the clo-"' sure opening comprising a memberhaving a portion overlapping the edge of said opening and anotherportion having an elongated slot alignable Withsaid oppositely extendingarms to receive said arms, means to hold the slotted member in aselected position, and means to mount the closure member in the openingof the cooling system with the pivotally mounted spring pressed membernormally urged to normal position and displaceable toward the interiorof said cooling system for introducing fluid to the system.

2. A closure mechanism for a cooling system for liquid cooled engineshaving an inlet opening therein, a closure therefor having means forattachment to said inlet, an opening in the 010- sure mechanism, meansto mount a gasket about said closure opening comprising an undercutgroove having an inclined side wall for holding the sealing gaskettherein, means to close one side of the closure opening comprising apivotally mounted spring pressed member, oppositely extending armscarried by said spring pressed mem-v ber and extending into saidopening, said spring pressed member having a sealing race forcooperation with the gasket, means to close the other side of saidclosure opening comprising a member having a portion overlapping theedge surroundingsaid opening and another portion having a locking slotalignable with said arms, engaging means and stops for said arms beingformed ateach edge of said locking slot, means to hold the slottedmember in a selected position with respect to said arms comprising aspring pressed detent, and means to attach the closure mechanism insealing relation to the inlet opening of the system with the pivotallymounted spring pressed members normally urged toward closed position anddisplaceable toward the interior of the system for introducing fluidthereinto.

3. A closure for cooling systems for engines in which a liquid coolingsystem is operable at considerable internal pressure, and having aninlet opening into such system, comprising a closure mechanism thereforhaving an opening, means to mount a gasket about said closure opening,means to close one side of the closure opening comprising a pivotallymounted spring pressed member, oppositely extending arms carried by saidspring pressed member extending into said opening, said spring pressedmember having a sealing face for cooperation with the gasket, said armsextending oppositely across said sprin pressed member to terminateadjacent the gasket contacting portion thereof to prevent the fillerspout from striking and damaging said gasket contacting portion, meansto close the other side of the closure opening comprising a memberhaving a portion overlapping the edge of said opening and anotherportion having an elongated slot alignable with said oppositelyextending arms to receive said arms, means to, hold the slotted memberin a selected position, and means to mount the closure member in theopening of the cooling system with the pivotally mounted spring pressedmember normally urged to normal position and displaceable toward theinterior of said cooling system for introducing fluid to the system.

MERLYN M. CULVER. LYLE L. DUNCAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

